1. Field of the Invention
The method relates to a method for the production of milk with a high proportion of melatonin and to milk products that can be obtained from it.
2. Discussion of Background Information
The principal secretion product of the epiphysis or pineal gland is the indolamine melatonin, discovered in 1958 by Lerner and which is produced via serotonin from the amino acid tryptophan. The effects of melatonin were examined in the following years. Positive effects can be achieved through the oral administration of melatonin, so that many possible applications have been developed in human medicine and in the field of nutritional supplements. However, synthetic melatonin of pharmaceutical origin must be used for this, because to date melatonin has not been available in sufficient amounts from natural sources.
Melatonin is a hydrophilic amino acid derivative. In the body it acts as a hormone and anti-oxidant. Numerous neurobiological functions have now been found in humans, such as for example “anti-ageing agent”, radical trap, regulator of the circadian clock and endogenous induction of sleep, as well as an influence on reproduction, the immune system, body temperature and brain activity. With humans and also with mammals the hormone melatonin is secreted by the pineal gland. During synthesis the amino acid tryptophan is decarboxylated and hydroxylated. From the serotonin thus formed melatonin is formed by N-acetylation and methylation (=N-acetyl-5-methoxyltryptamin).
The use of milk enriched with melatonin or milk products made from it against the increasing reduction of the melatonin level with age would be a logical concept, for example, from a scientific point of view. The daily level of melatonin in the blood is about 20 to 70 pg/ml for young people (20-30 years old). It increases at night to about 125 pg/ml. This range of concentration would have to be reached after the consumption of milk or milk powder. With oral administration melatonin is however subject to a relative high first-pass mechanism, i.e. about 30% is metabolised by the liver and eliminated and therefore does not occur at an effective level in the blood. Therefore, about a 30% higher amount has to be taken orally to obtain the desired target concentration.
Melatonin from natural sources is to date only available with restrictions. Previously slightest concentrations have been found in a few species of plants. There is however no method for the systematic extraction and no natural store for keeping foodstuff rich in melatonin. Studies and research into the medicinal effectiveness and biological availability of naturally produced melatonin have to date not been published. The extent to which naturally extracted melatonin differs from the pharmaceutically produced melatonin with regard to its biological effect and availability has to date not been sufficiently investigated.
It is known that melatonin occurs in traces in the blood plasma of humans and mammals and is continuously reproduced. Melatonin bound to blood plasma is however not suitable for use in human medicine or as a nutriment or nutritional supplement.
In contrast, a well-known foodstuff produced with the aid of blood in the body of various mammals is suitable for the extraction of natural melatonin, namely milk. Here, the melatonin is in particular bound to the milk protein.
For humans it is known that the change of light irradiation is important for the control of the behaviour related to the time of day and seasons. The light/darkness cycles control many behavioural patterns of humans, including winter depression, sleeping/awake cycles, body temperature, brain activity, subjective awareness and performance. These influences known in humans also largely apply to mammals.
All animals are adapted to the cyclic change of day and night. So-called internal clocks control all important life functions such as the metabolism, body temperature, the hormone and immune systems as well as the behaviour on a daily cycle. The 24-hour cycle of this internal pacemaker is however not controlled by external time information. This so-called circadian system also functions in the absence of external factors, but does not correspond exactly to one day. The expression “circadian” is derived from the Latin expressions “circa” (approximately) and “dies” (day).
The synchronisation of the internal pacemaker with the external day/night cycle occurs via time generators, external stimuli, which convey information about the time of day to the body. The most important time generator for mammals is light. But also factors such as temperature, activity and social interaction can offset the circadian cycle. There are many indicators that the circadian system with mammals can be synchronised by light exclusively via the retina, wherein information about the light conditions is essentially received through retinal photoreceptors.
The normal husbandry methods now employed for lactating mammals allow the animals to move freely and they can freely go to their bedding down, feeding and milking positions both during the daytime and at night. The livestock quarters are usually equipped with white-coloured emergency lights at night, so that the animals can differentiate between friend and foe and can find their desired destinations. Conventional illumination systems of this nature reduce the production of melatonin in the night.
In WO 01/01784 a method for the production of milk rich in melatonin is described in which the daily cycle of mammals is divided into one light and one dark period and the animals are milked at the end of the dark phase. The amount of light during the dark period is preferably below 40 lux. Also in GB-A-2387099 a method for the production of milk rich in melatonin is described in which the daily cycle of mammals is divided into one light and one dark period, wherein the light intensity in the dark period should not exceed 50 lux. Also experiments in darkening and the use of black light in the dark period are described.
The previously known methods have a common feature in that in the “dark phase” of keeping the animals the lowest possible amount of light is regarded as mandatory. This is however associated with difficulties, because the animals can only orientate themselves with difficulty or not at all during this dark phase due to the lack of or inadequate light, which is not practicable in particular during the milking process. The melatonin content of the milk is thus negatively influenced.
In particular if the animals are kept in a shed and in a large number, the lack of orientation represents a serious problem. Therefore the above described methods are at best suitable for small farms. For larger herds of animals in free-ranging systems these methods are hardly practicable according to the state of the art. Industrial production relevant to the market is thus hardly possible.
The object of the invention under consideration is therefore the provision of a method for the production of milk with increased melatonin content which facilitates adequate orientation for the animals and also for the operating personnel during the night and which is also suitable for an increased number of animals.
These objects were surprisingly able to be solved by a method for the production of milk with increased melatonin content or milk products of it, in which the daily cycle of one or more female mammals is divided into a daytime phase under a first light regime with a proportion of blue light and a night-time phase under a second light regime and the animal or animals are milked at least once during the night-time phase in order to obtain milk with a high melatonin content, characterised in that during the night-time phase at least one light source is used for the light regime, which emits light in the wavelength range of 500 nm or more and essentially no light is emitted in the wavelength range below 500 nm. The light source in particular emits light of the colour yellow, orange, amber or red or a mixed colour of these, wherein red light is especially preferred.
With the invention presented here a method is described in which, with the use of appropriate light regimes, the circadian cycle and the melatonin suppression in the animals are influenced such that milk with increased melatonin content is obtained. In achieving this, the animals are despite this kept in the night-time phase under a light regime which ensures adequate orientation. Thus, the method can also be employed with a larger number of animals.